Surgical trauma occurs to blood vessels such as the human saphenous vein (HSV) when it is harvested from the lower extremity and transplanted into the arterial circulation as an arterial bypass graft. This project will determine the molecular mediators that lead to decreased function of HSV and blood vessels after surgical injury. Since ?the response to injury? has been implicated in modulating vein graft failure, a better understanding of the molecular mechanisms of surgical trauma would decrease myocardial infarction, re-do operations and limb loss associated with vein graft failure. This work will also provide new insights in pathologic surgical injury with potential extensions to other applications such as vascular injury during angioplasty, transplantation, and trauma.